Dual chamber pacemaker therapy for mid-cavity obstructive hypertrophic cardiomyopathy

Intracavitary LV obstruction is an important determinant of clinical outcome in hypertrophic cardiomyopathy (HCM). In a minority of patients the obstruction is at the level of the papillary muscles. Mid-cavity obstructive HCM may be associated with a distal LV aneurysm and a worse prognosis. It is often not amenable to standard cardiac surgeryfor LV outflow obstruction. The long-term effects (mean follow-up 4.8+/-2.9 years) of dual chamber (DDD) pacemaker therapy in 14 patients with mid-cavity obstructive HCM (mean age 34+/-16 years, range 15-65 years) were studied. Patients were evaluated by cardiac catheterization at baseline and 6 months to 1 year after receiving DDD pacemakers off all drug therapy. Symptoms were improved in all patients and NYHA functional class reduced from 2.8+/-0.1 to 1.9+/-0.4 (P < 0.0005). Intracavitary LV pressure gradients was reduced significantly (43+/-36 vs 84+/-31 mmHg at baseline, P < 0.0005). There was a significant associated reduction in apical LV systolic pressure (152+/-37 vs 188+/-34 mmHg, P < 0.001). In addition, there was a trend towards increased exercise tolerance (445+/-123 vs 396+/-165). Cardiac output and LV filling pressures were unchanged. In conclusion, chronic DDD pacing results in significant symptomatic and hemodynamic improvement in this uncommon but important subset of patients with obstructive HCM in whom the role of cardiac surgery is less well defined compared with the more typical outflow tract location of LV obstruction.     

The importance of ventricular septal morphology in the effectiveness of dual chamber pacing in hypertrophic obstructive cardiomyopathy

It has been reported that older patients with hypertrophic obstructive cardiomyopathy (HOCM) benefited the most from dual chamber (DDD) pacing. Since in older patients the distribution of septal hypertrophy and left ventricular (LV) cavity shape differs from that in younger patients, we decided to study the efficacy of DDD pacing on the reduction of LV outflow tract (LVOT) gradient in different patterns of septal hypertrophy. We compared HOCM patients with nonreversed septal curvature, thus preserving the elliptical LV cavity contour (common in the elderly), (group I) versus patients with reversed septal curvature, deforming the LV cavity to a crescent shape (common in the young), (group II). Eighteen HOCM patients were studied (11 patients in group I and 7 patients in group II). After implantation of a DDD pacemaker, the LVOT gradient was measured using Doppler echocardiography at various programmed AV delay intervals to determine the maximal percentage decrease of LVOT gradient from baseline. The measurement was repeated after at least a 6-month follow-up (chronic DDD pacing). The baseline LVOT gradient was comparable between groups (79 +/- 28 vs 81 +/- 25 mmHg, P = 0.92). The LVOT gradient reduction at acute DDD pacing was significantly greater in group I than group II (61 +/- 18% vs 23 +/- 10%, P = 0.0001). This difference in favor of the patients from group I was maintained at midterm follow-up (69 +/- 17% vs 40 +/- 17% P = 0.0076). In conclusion, patients with normal septal curvature and preserved elliptical LV cavity shape had a greater reduction of LVOT gradient after DDD pacing than patients with reversed septal curvature deforming LV cavity. The proposed criterion assessing the septal curvature may be useful to predict the efficacy of DDD pacing in the reduction of LVOT gradient.     

Impact of chronic DDD pacing on time-domain indexes of heart rate variability in patients with hypertrophic obstructive cardiomyopathy

The aim of this study was to examine whether DDD pacing affects time-domain indexes of heart rate variability (HRV) in patients with hypertrophic obstructive cardiomyopathy (HOCM). We studied 11 patients (7 men, age 52 +/- 8 years) with HOCM refractory to drugs. In all patients a DDD pacemaker was implanted and the atrioventricular delay was programmed to ensure a full ventricular activation sequence. Time-domain indexes of HRV (mean NN, SDANN, SDNN, SD, rMSSD, pNN50) were determined from 24-hour Holter recordings 3 days before and 1 year after pacemaker implantation. The pacemaker was turned off during the second recordings. The same indexes were determined in ten healthy controls at the same time points. The controls showed no significant differences in any of the measured parameters between the two time points. The HOCM patients showed an increase in SD (from 27 +/- 13 to 41 +/- 13 ms, P < 0.001), rMSSD (from 18 +/- 5 to 32 +/- 8 ms, P < 0.001), and pNN50 (from 1.03 +/- 1.06 to 8.52 +/- 4.84%, P < 0.0001). As a result, the values of these three parameters, which were lower in the HOCM patients than in the controls before pacing, were restored to normal levels by the end of the study. In conclusion, our findings indicate that long-term pacing in HOCM patients restores the sympathovagal balance in the heart by increasing vagal activity.     

组织多普勒成像评价肥厚型心肌病患者心脏舒张功能

目的 探讨组织多普勒成像评价肥厚型心肌病舒张功能的价值.方法 回顾性对比分析肥厚型心肌病组(60例)及正常对照组(30例)超声心动图检查结果,比较组织多普勒参数与常规超声参数评估左室舒张功能的价值.结果 肥厚型心肌病组左心房前后径、面积、室间隔厚度、室间隔与左室后壁厚度比值(IVS/LVPW)、二尖瓣E峰速度与二尖瓣环舒张早期峰值速度比值(E/Em)和左心室充盈压均显著高于对照组(P<0.01),E/A在两组差异无统计学意义(P=0.67),Em显著低于对照组E(7.84±2.43)cm/s对(10.87±2.18)cm/s,P<0.01].肥厚型心肌病组E/Em与左房前后径及面积有相关关系(分别r=0.331,P=0.017;r=0.325,P=0.019),而E/A与二者无相关性.结论 组织多普勒参数(Em,E/Em)是评价肥厚型心肌病患者心脏舒张功能的敏感方法.     

Cardiac magnetic resonance in hypertrophic cardiomyopathy: current state of the art

Hypertrophic cardiomyopathy is a complex disorder with significant heterogeneity in clinical characteristics and natural history. Traditionally, the diagnosis has been based on clinical assessment and echocardiography; however, persistent challenges in its noninvasive evaluation remain. Hence, improved diagnostic techniques could lead to better risk stratification of patients, which would potentially identify patients likely to benefit from effective therapies. Recent studies have demonstrated the increasing utility of cardiac magnetic resonance in the management of this disease. With the increasing utilization of genetics, cardiac magnetic resonance is likely to play an even more important role in discerning the subtle morphologic differences seen in such patients with similar genotypic profiles.     

通心络胶囊对原发性肥厚型心肌病左室功能影响的观察

目的：观察通心络胶囊对原发性肥厚型心肌病（HCM）2E室功能的影响。方法：18例原发性HCM患者治疗前停用一般治疗药物，然后给予通。t3络胶囊，每次3粒，饭后服用，每日3次，连服4周。用药前及用药后使用彩色多普勒超声和。t3电图检查测定左室收缩和舒张功能。结果：与用药前比较，用药后患者的左室射血分数（LVEF）、心排血量（CO）、左室短轴收缩率（AFS）、心房充盈分数（AFF）均无明显改变，差异均无显著性（P均〉0．05）；等容舒张时间（IRT）、慢充盈分数（SFF）均显著下降，二尖瓣前叶斜率、平均快速充盈速度（MRFV）、快充盈分数（RFF）及标准化快充盈（RFR／EDV）均显著升高，差异均有显著性（P均〈0．01）。用药后。t3率显著减慢（P〈0．05），但动脉收缩压（SBP）和左室收缩末期内径（LVESD）均无明显改变（P均〉0.05）。结论：通心络胶囊可显著改善原发性HCM患者的左室收缩和舒张动能，对治疗原发性HCM具有较好疗效。     

双腔起搏治疗肥厚型梗阻性心肌病长期随访研究

目的 评价起搏器治疗肥厚型梗阻性心肌病(HOCM)患者的长期疗效,探讨临床特异的超声心动图评价指标.方法 连续选取我院37例植入双腔起搏器的HOCM患者进行随访,其中37例随访1年,26例随访2年,10例随访3年.分别于起搏器植入后1年、2年及3年,测试起搏频率、阈值、阻抗、房室延迟、心房和心室起搏百分比,超声测量左房内径(LAD)、左室舒张末内径(LVEDd)、左室后壁厚度(LVPW)、室间隔厚度(IVS)、左室流出道内径(LVOTd)、左室流出道压力阶差(LVOTPG)、左室射血分数(LVEF)、肺动脉收缩压(PASP),观察收缩期二尖瓣前向运动(SAM).动态比较起搏器植入前后起搏参数及超声心动图指标变化.结果 调整起搏频率60～70次/min,调整房室延迟90～180 ms,以满足95％以上心室起搏,心房、心室起搏阈值和起搏阻抗正常范围内,3年内起搏器各参数差异无统计学意义(P＞0.05);与起搏前相比,起搏治疗1、2和3年后,IVS及LVOTPG显著下降(P＜0.01),LVOTd显著增宽(P＜0.01),SAM现象明显改善(P＜0.01),但LAD、LVEDd、LVPW、LVEF及PASP起搏前后变化差异无统计学意义(P＞0.05).结论 双腔起搏治疗HOCM可长期改善其心脏结构重构.IVS、LVOTd和LVOTPG可以作为长期评价起搏治疗HOCM的敏感和特异的超声指标.     

定量组织多普勒速度成像评价肥厚型心肌病左室功能的研究

目的:探讨定量组织多普勒速度成像技术(QTVI)评价肥厚型心肌病(HCM)患者左室心肌收缩与舒张功能的价值。方法:应用QTVI获取30例正常人和30例HCM患者左室长轴方向不同室壁即左室前壁、后壁、下壁、侧壁及室间隔的心肌多普勒速度曲线。分别测量正常人与HCM患者上述不同左室壁心肌运动收缩期峰值速度(Vs)、加速度(a)、快速充盈期和心房收缩期的速度(Ve和Va)、收缩期内外膜峰值速度阶差(MVG)、二尖瓣舒张期血流频谱E/A值、左室射血分数(LVEF)、Ve/Va值。比较正常人与HCM患者室间隔、HCM患者室间隔与左室其它室壁间的上述参数的差异。结果:①HCM患者肥厚室间隔的Vs、Ve、Va、MVG、a均比正常人室间隔明显降低(P<0.05);②HCM患者E/A比正常人低,Ve?蛐Va与E?蛐A有轻度的相关关系(r=0.734)。③非梗阻型HCM患者肥厚室间隔厚度IVSt与Ve/Va有负相关关系(r=-0.614)。④HCM患者E/A值比正常人低(P<0.05)。结论:QTVI可定量评价HCM患者左室心肌功能,为进一步了解HCM局部心肌收缩舒张功能变化及其局部与整体心肌功能变化关系提供较为敏感、精确的方法。     

超声引导下经皮室间隔消融术治疗肥厚型梗阻性心肌病研究进展

对有症状的肥厚型梗阻性心肌病,如何有效解除左心室流出道梗阻是治疗的重点,依靠药物、双腔起搏的方法以减轻左心室流出道压力阶差可缓解症状,而减少室间隔厚度的方法包括外科间隔心肌切除术、经皮室间隔心肌化学消融术、室间隔射频导管消融术等,这些方法在减少室间隔厚度上均有明显效果。超声引导下经皮室间隔心肌热消融术作为一种侵入性较小、效果较好的治疗方法,在肥厚型心肌病的治疗中有较大应用前景。本文就超声引导下经皮室间隔消融术治疗肥厚型梗阻性心肌病的研究进展作一综述。     

Effect of cardiac resynchronization on gradient reduction in patients with obstructive hypertrophic cardiomyopathy: preliminary study

Background: The purpose of this study was to assess the effectiveness of cardiac resynchronization therapy (CRT) in terms of outflow tract gradient reduction and functional improvement in symptomatic patients with hypertrophic obstructive cardiomyopathy (HOCM) requiring implantable cardioverter‐defibrillator (ICD) implantation. Methods: Eleven consecutive symptomatic HOCM patients with a significant (≥40 mmHg) gradient and indications for ICD, but without indications for resynchronization, underwent CRT‐D implantation. Nine of them (four female, median age of 50 years) in whom the procedure succeeded were screened for New York Heart Association (NYHA) class, outflow gradient, mechanical dyssynchrony, QRS‐width change, and 6‐minute walking distance (6MWD) and peak oxygen consumption (VO₂peak) improvement after 6 months and remotely. Results: After 6 months of pacing, NYHA class decreased (median 1 vs 2, respectively); peak (33 vs 84 mmHg) and mean (13 vs 38 mmHg) outflow tract gradients were reduced; and QRS width (143 vs 105 ms), intraventricular dyssynchrony (35 vs 55 ms), and VO₂peak (19.5 vs 14.2 mL/kg/min) increased significantly (all P < 0.05) compared to baseline. In six of nine patients (67%), the peak gradient was reduced >50% and reached <40 mmHg. After a median of 36 months, the outflow gradient decreased even more (8 mmHg) and was significantly (P < 0.05) lower than after 6 months of CRT. Conclusions: These preliminary data suggest that CRT seems to be an effective method of reducing the outflow tract gradient and improving the functional status of symptomatic HOCM patients requiring ICD implantation. Our findings need to be confirmed by more extensive studies. (PACE 2011; 34:1544–1552)     

Device therapy in hypertrophic cardiomyopathy

With increasing awareness of the condition and particular attention being paid to family screening, the number of patients being diagnosed with hypertrophic cardiomyopathy is increasing. Although the majority of patients remain at low risk for sudden cardiac death, all patients need to undergo rigorous and ongoing risk factor stratification in order to best identify those at high risk. Although implantable cardioverter–defibrillators have proven to be effective in the prevention of sudden cardiac death, careful consideration of device implantation in high-risk patients is necessary in view of the potential for device complications and their impact on quality of life.     

Surgical management of obstructive hypertrophic cardiomyopathy: the gold standard

While medication is the first line of therapy in obstructive hypertrophic cardiomyopathy, patients who have symptoms refractory to medical treatment or asymptomatic patients with high resting gradients (≥30 mmHg) may require septal myectomy. Surgical septal myectomy can be performed safely, with excellent survival, relief from symptoms and low morbidity. Alcohol septal ablation is an alternative to surgical treatment, but late outcomes are uncertain. Although both methods of septal reduction relieve left ventricular outflow tract gradients and improve functional status, the need for permanent pacing appears higher with alcohol ablation compared with surgical myectomy. As our understanding of obstructive hypertrophic cardiomyopathy continues to grow, the indications for intervention will evolve. In our practice, septal myectomy remains the gold standard for treatment of obstructive hypertrophic cardiomyopathy.     

Long-term follow-up after percutaneous septal ablation in hypertrophic obstructive cardiomyopathy

OBJECTIVES: The aim of this study was to evaluate the longterm follow-up results of percutaneous transluminal septal myocardial ablation (PTSMA) in a large patient cohort. BACKGROUND: PTSMA by alcohol injection into septal branches has shown good acute and short-term results in symptomatic patients with hypertrophic obstructive cardiomyopathy. METHODS: A total of 100 consecutive symptomatic (NYHA class 2.8 +/- 0.6) patients underwent PTSMA. All patients had clinical and non-invasive follow-up at 3 months, 1 year, and annually up to 8 years. RESULTS: One patient died at day 2 after intervention due to fulminant pulmonary embolism following deep venous thrombosis, and eight patients required a permanent DDD-pacemaker due to post-interventional complete heart block. Acute reduction of the left ventricular outflow tract gradient was achieved from 76 +/- 37 to 19 +/- 21 mmHg at rest, from 104 +/- 34 to 43 +/- 31 mmHg during Valsalva maneuver, and from 146 +/- 45 to 59 +/- 42 mmHg post extrasystole (p < 0.0001, each). During follow-up (mean follow-up time: 58 +/- 14 months), three additional patients died (sudden death at 48 months, non-cardiac death at 49 months and stroke-related death at 60 months after the index procedure). All living patients showed clinical improvement to NYHA-class 1.4 +/- 0.6 (after 3 months, n = 99), 1.5 +/- 0.6 (after 1 year, n = 99), and 1.6 +/- 0.7 at final follow-up (n = 96; p < 0.0001, each). Non-invasive follow-up studies documented ongoing outflow tract gradient reduction, decrease of septal and left ventricular posterior wall thickness, and improvement of exercise capacity. CONCLUSIONS: PTSMA is an effective treatment for symptomatic patients with hypertrophic obstructive cardiomyopathy. Follow-up showed ongoing hemodynamic and clinical improvement without increased mortality and morbidity.     

心脏磁共振评价心尖肥厚型心肌病患者左心房室结构、功能及其相关性研究

目的用心脏磁共振评估心尖肥厚型心肌病(apical hypertrophic cardiomyopathy,AHCM)患者心脏形态及左心室舒张功能变化,并评估左心室舒张功能与心尖部厚度及左房形态、功能之间的关系。材料与方法回顾性分析2015年9月至2018年7月于我院就诊并完成心脏磁共振、心电图及超声心动检查的患者,挑选出其中AHCM患者69例及健康对照组25例,比较两组之间左心室射血分数(left ventrical ejection fraction,LVEF)、左心室心肌质量、左心室心肌厚度、收缩末期左房容积(left atrial end systolicvolume,LAESV)、左房整体峰值纵向应变(left atrial peak global longitudinal strain,LAPGLS)、左房整体峰值周向应变(left atrial peak global circumferential strain,LAPGCS)及左房面积变化分数(fraction area change,FAC)的差异,以及LAPGLS和LAPGCS与其他左心房室结构及功能参数之间的相关性。结果心尖肥厚型心肌病组左心室心尖部厚度、左心室心肌质量、LVEF、LAESV均明显高于正常对照组,LAPGLS及FAC均明显低于正常对照组,两组之间的差异均有统计学意义(P<0.05),而两组之间的LAPGCS差异则没有统计学意义。结论心尖肥厚型心肌病患者左心室舒张功能下降,而左心房收缩功能未发生明显变化。左心房FAC可作为LAPGLS的替代指标来判断左心室舒张功能是否下降。     

定量组织速度成像对肥厚型心肌病左心室局部心肌舒张功能的分析

目的探讨定量组织速度成像（QTVI）评价肥厚型心肌病（HCM）患者左室局部心肌舒张功能的价值。方法获标准心尖长轴切面、心尖二腔切面和心尖四腔切面，应用QTVI技术分析17例HCM患者和18例健康者左室长轴方向不同室壁节段的多普勒速度曲线，测量各节段心肌运动舒张早期峰值速度（Ve）和舒张晚期峰值速度（Va），计算左室二尖瓣环、基底段、中段水平的平均Ve、平均Va。应用脉冲多普勒技术分别测量二尖瓣口舒张早期峰值速率（E）、舒张晚期速率（A）、计算E／A。结果HCM组左室各节段Ve明显低于正常组（大部分P〈0．001），肥厚节段Va低于正常组（P〈0．05），而非肥厚节段Va两组间差异无显著性意义（P〉0．05）。两组同一水平平均Ve、Va的比较均有显著性意义（P〈0．05）。HCM组与正常组二尖瓣口E、A、E／A差异无显著性意义（P〉0．05）。结论QTVI能定量评价HCM患者左室局部心肌舒张功能。HCM患者左室长轴各节段心肌松弛性显著降低，肥厚节段的心肌顺应性受损。     

“Burnt out” dilated hypertrophic cardiomyopathy causing acute LVAD thrombosis

Case report illustrates obstruction encountered in a patient with end‐stage dilated hypertrophic cardiomyopathy (HCM) who underwent LVAD implantation. The morphology reversed in early postoperative period to HCM. Pump replacement required coring of the ventricular muscle. Dilated end‐stage hypertrophic cardiomyopathy can revert back to the original morphology on decompression.     

多普勒组织成像鉴别肥厚型心肌病舒张功能假性正常

目的　探讨应用多普勒组织成像 (DTI)二尖瓣环舒张速度鉴别肥厚型心肌病舒张功能假性正常。方法　在正常人与肥厚型心肌病患者中应用脉冲多普勒技术分别测量二尖瓣口舒张早期峰值速率 (E)、舒张晚期峰值速率 (A) ,肺静脉收缩波 (S)、舒张波 (D)及心房收缩波 (Ar)。转换DTI速度模式 ,测量二尖瓣环各点舒张早期峰值速率 (Ea)、舒张晚期峰值速率 (Aa)并计算Ea/Aa。结果　肥厚型心肌病舒张功能假性正常患者与正常人二尖瓣E、A、E/A差异无显著性意义 (均 P >0 .0 5 ) ,肺静脉S、S/D、Ar差异有显著性意义 (均 P <0 .0 1) ,二尖瓣环Ea及Ea/Aa差异有显著性意义 (P <0 .0 1) ,Aa差异无显著性意义 (P >0 .0 5 )。结论　多普勒组织成像二尖瓣环Ea及Ea/Aa可鉴别肥厚型心肌病舒张功能假性正常     

超声左心室压力-应变环评价肥厚型心肌病

目的 观察超声左心室压力-应变环（PSL）评价肥厚型心肌病（HCM）患者左心室收缩功能的价值,评价心肌做功（MW）参数与常规舒张收缩功能、左心室应变参数间的相关性。方法 纳入43例HCM患者（HCM组）与49名健康志愿者（对照组）,比较组间常规超声参数、应变参数和MW参数。绘制受试者工作特征（ROC）曲线,计算曲线下面积（AUC）,评价各参数诊断HCM的效能。采用Pearson或Spearman相关分析评估常规超声参数、应变参数与MW参数间的相关性,以多元线性回归分析与MW独立相关的参数。结果 HCM组室间隔舒张末期厚度（IVSD）、左心室后壁舒张末期厚度（LVPWD）、左心房前后径（LAD）、容积指数（LAVI）、A峰流速、E/A、E/e''、左心室心内膜下心肌圆周应变（CS-Endo）、左心室整体扭转应变（Twist）、峰值应变离散度（PSD）及整体无效功（GWW）均明显高于对照组（P均<0.05）,舒张早期二尖瓣环侧壁（Lateral e''）、室间隔运动速度（Septal e''）、e''、左心室舒张末期容积（LVEDV）、收缩末期容积（LVESV）、左心室中层心肌（CS-Mid）、心外膜下心肌圆周应变（CS-Epi）、左心室整体纵向及分层应变、整体做功指数（GWI）、整体做功效率（GWE）均明显低于对照组（P均<0.05）。MW指标、左心室整体纵向应变（LVGLS）及PSD诊断HCM的效能均较高（AUC均>0.80）。对照组MW参数与传统收缩舒张功能参数、LVGLS及PSD多呈中度相关,且具有独立相关性（P均<0.05）;HCM组不同方向整体和分层应变、PSD及A峰流速均多与MW参数呈低度及以上相关,且具有独立相关性（P均<0.05）。结论 超声PSL技术可无创评估HCM患者左心室收缩功能;MW参数与常规舒张收缩功能、左心室应变参数具有一定相关性。     

三维斑点追踪技术评价肥厚型心肌病左室扭转功能

摘 要 目的 应用三维斑点追踪成像（3D-STI）技术评价肥厚型心肌病（HCM）患者的左心室收缩功能。 方法 病例组选取19例HCM患者及对照组年龄、性别均匹配的19例健康志愿者,行常规二维超声心动图检查,留取三维图像并存储。三维图像用4D-Auto LVQ进行分析,得到左室各水平旋转角度曲线,计算得出左室整体扭转角度（twist）及扭力（torsion）,比较两组之间的差异。 结果 与对照组比较HCM组整体扭转角度及扭力均增加,整体纵向应变减低,差异显著有统计学意义（P<0.01）。HCM组二尖瓣水平旋转角度、二尖瓣水平及心尖水平扭力均增加,差异有统计学意义。 结论 HCM患者的左心室扭转增加,长轴应变减低,心肌功能不同程度受损。3D-STI可以反映HCM患者左心室整体及各水平收缩功能的变化。